Expansion of e.g.f. exp(x) * Product_{k>=1} (1 + x^k/k!).

Terms

a(0) =1a(1) =2a(2) =4a(3) =11a(4) =32a(5) =97a(6) =355a(7) =1423a(8) =5696a(9) =23141a(10) =108149a(11) =559693a(12) =2913971a(13) =14806365a(14) =75692999a(15) =432849976a(16) =2780749376a(17) =18237870285a(18) =115493756737a(19) =708062095921